Justin Timberlake: #hashtags with Fallon, concert with Kimmel

Justin Timberlake and Jimmy Fallon know just how #ridiculous the hashtag frenzy has become.

Timberlake, 32, who's all over the media this week promoting the next installment of his album "The 20/20 Experience: 2 of 2," out Monday, appeared in a pre-recorded segment for "Late Night" on Tuesday just to have a little hashtag conversation about what he and his "History of Rap" collaborator have been up to. The kicker? They utilized the overwrought social media colloquialism in an everyday verbal repartee.

The pair talked about everything -- #chillin #working #homemade #oatmealraisin cookies #cookiemonster #lololololololololololololol #orangeisthenewblack #barney #dinosaurs #iceage #rayromano #halloween #lifedecisions #monalisa #ninjaturtles #dentalcare #wecantstop and #shutthe...up. That last one came courtesy of Fallon's "Late Night" band leader Questlove and is exactly how we feel when we see nonsensical paragraph-long hashtags.

So, thank you boys. Consider this a public service announcement and a demonstration of the proper way to finger-mimic the hashtag in conversation. (Watch the #banter in the video above).

Timberlake, who released his latest single "TKO" on Friday, also braved illness earlier in the evening to perform a six-song set for "Jimmy Kimmel Live!" Kimmel's free two-day concerts also featured Paul McCartney on Monday and shut down a stretch of Los Angeles' Hollywood Boulevard through Wednesday morning, L.A. Now reported.

"I'm gonna need your help tonight," the singer told the outdoor concertgoers before he sang "Mirrors." "If I'ma do this, I need to hear everyone singing. I don't want to see you big-time me. I know this is Hollywood."

The 'N Sync alum took a nearly seven-year hiatus before releasing any new music on his own. The second part of his comeback album comes after the March release of the first part; the 11-track sequel is currently being streamed on iTunes about a week before its official release.

He has also announced that he'll be launching a world tour to promote the album, with the North American leg starting at the Bell Centre in Montreal, Canada, on Oct. 31. "The 20/20 Experience World Tour" follows his summer stadium tour co-headlining with rapper Jay Z, "Legends of Summer."